[JHamilton]

Hi Guys. I am new to this forum and have a general question. I have recently bought a 77 KZ 1000 in pretty good shape. Cleaned carbs, few other minor repairs, and now ready to ride. I changed the oil and filter and when I started the engine the o ring on the filter cover blew out and deposited a couple of quarts of oil on the shop floor. I assumed that I had failed to get the filter bolt tight so I replaced the o ring and filter and checked to make sure all bolts were tightened properly..... Would you believe the same thing happened when I started the engine again. Now I am wondering what I am doing wrong. Any help wouild be appreciated.

Thanks,

John

 

[notabiker]

CHECK THE COVER FOR BEING FLAT,
before you did the work did it run without leaking ?. if so some how you created the problem. back track and start over. i doubt you have to much oil pressure. these old roller bearing crank engines run low oil pressure.

 

[kawtoy_77]

CHECK THE COVER FOR BEING FLAT,
before you did the work did it run without leaking ?. if so some how you created the problem. back track and start over. i doubt you have to much oil pressure. these old roller bearing crank engines run low oil pressure.

I have one of these beasts you speak of, but even re-using an old O-ring on the cover I have never heard of, or seen this happen. Is the crankcase vent clear of obstruction?

 

[JHamilton]

As far as I can tell it is clear. I have taken it off and did not see anything that might cause a restriction.

John

 

[JHamilton]

It did run without leaking as far as I know. The previous owner did remove an oil cooler that was leaking and plug the holes in the block. I can't imagine that causing the o ring to blow out.

John

 

[jrick56]

had a 79 for 10 years never had that happen. some thing is allowing too much pressure to build up. i don't think even a plugged vent would do that. something in oil system is letting too much pessure buildup. maybe some thing to do with the bypass valve. what fitler are you using?:screwy::screwy::screwy:

 

[jrick56]

also make sure you installing all the washers spring and cover correctly. never liked doing oil changes on mine or my zrxes for that matter they use the same filter. may be able to scan a pic of the assembly if you need one. i'll check if you want.:screwy::screwy::screwy:

 

[JSharp]

It did run without leaking as far as I know. The previous owner did remove an oil cooler that was leaking and plug the holes in the block. I can't imagine that causing the o ring to blow out.

John

How exactly did he remove the cooler? The normal connection point for a cooler on those engines was at the manifold elbow on the top of the crankcase behind the cylinders. The return from the cooler was to the top of the main oil galley or to the same galley on the right side of the crankcase. Again, all of that is behind the cylinders.

To use a cooler you needed a different oil manifold elbow setup.

You can't just block off the outlet port on one of the modified elbows or whatever piping they used to connect the cooler. That will stop all oil feed to the engine and deadhead the oil pump possibly blowing the filter o ring...

 

[JHamilton]

To all:
I believe I have solved this mystery. The original oil sending unit manifold was a one-piece unit that encompassed two oil ports. When the oil cooler was installed, this one-piece manifold was replaced with two separate manifolds each covering one port. The previous owner did not know this as he did not install the cooler. When he removed the cooler.......cause it was leaking..... he simply plugged both manifolds...thus creating the problem. He did not even know this was a problen as he had not started the engine since removing the cooler. The bike had set up for a while and the carbs needed cleaning when I bought it. It was only after I went through the carbs and started the engine that this was discovered. Lesson learned. If I had compared the picture of the factory oil manifold as shown in the repair manual I would have noticed that it looked different than what is actually on the motorcycle.

Thanks for all your help.

John

 

[kawtoy_77]

Glad to hear the mystery is solved! Enjoy the bike.

 

[JSharp]

To all:
I believe I have solved this mystery. The original oil sending unit manifold was a one-piece unit that encompassed two oil ports. When the oil cooler was installed, this one-piece manifold was replaced with two separate manifolds each covering one port. The previous owner did not know this as he did not install the cooler. When he removed the cooler.......cause it was leaking..... he simply plugged both manifolds...thus creating the problem. He did not even know this was a problen as he had not started the engine since removing the cooler. The bike had set up for a while and the carbs needed cleaning when I bought it. It was only after I went through the carbs and started the engine that this was discovered. Lesson learned. If I had compared the picture of the factory oil manifold as shown in the repair manual I would have noticed that it looked different than what is actually on the motorcycle.

Thanks for all your help.

John

Yep, as I said in the previous post that's just what I thought had happened. Not the first time I've heard of it. The nice thing is you have the fittings to install a cooler already. Pull the plugs and get a cooler and some hose and you're all set.

I don't know long the engine ran with no oil pressure but you might take a look at the cam bearings. Those engine have little oil pressure in normal operation thanks to the roller bearing crank. The downside is the plain bearings the cam rides in take a beating if there's any oil starvation. Thankfully Kawasaki was smart enough to use replaceable bearing shell inserts instead of just running the cams directly in the head like most manufactures.

Enjoy your bike! I rode a ton of miles on the Z1 family of bikes.